Mean (SD) values from 12 immobilized black rhinoceroses (Diceros bicornis) in Namibia during investigations comparing the physiology of lateral position with aerial suspension by the feet. The animals were in lateral recumbency or suspended by their feet before data were collected. Each rhinoceros received both treatments sequentially, in random order. These data are subdivided by the order (first or second) in which each treatment (lateral recumbency or suspension by the feet) was applied. P_aCO₂ (arterial carbon dioxide pressure) and P_AO₂ (alveolar oxygen pressure) are the only parameters where the order of treatment had a significant effect. The alpha value for comparisons was 0.05.